Active Metal Brazing Ceramic

Ceramic brazing with metallic fillers utilizes either premetallized ceramic surfaces or braze foils pastes or wires that usually contain a reactive filler metal such as ti which promotes braze wettability and flow characteristics by inducing chemical reactions with the ceramic.

Active metal brazing ceramic.

Active metal brazing is a joining method where ceramics can be joined to metals or itself through a brazing alloy known as active brazing alloy aba under the application of heat and pressure. Active metal brazing is used mainly for joining ceramics that are not wetted by conventional brazes. Active metal braze alloys eliminate process steps allowing you to braze directly to raw ceramics with prior heal firing without having to metalize plate the surface prior to brazing. When joining ceramics to metals with the brazing method for example metallization on the ceramic surface is necessary with general inactive brazing filler metal or the use of active brazing alloys in order to get a reliable joint.

Therefore the type and concentration of the added active element in the brazing alloy are crucial to the joint strength. The thermal expansion coefficients of ceramics are generally much lower than metals. To encourage wetting there are two basic philosophies apply something to the surface of the ceramics so that the braze will wet or put something in the braze that will induce wetting. Active brazing filler metals our active brazing filler metals enable direct ceramic brazing.

Depending on joint geometry active metal bonds should not necessarily be considered as strong as moly manganese bonds and may require empirical testing. Active brazetm no 10 brazing paste grade b420p 80 provides a silver copper titanium type active brazing filler metal in paste form and is intended principally for brazing non metallised alumina ceramics to a metallic substrate. In active metal brazing a metal usually titanium is added to the braze alloy to promote reaction and wetting with a ceramic substrate. Active brazing alloys active brazing alloys aba eliminate the need for traditional ceramic metallisation prior to brazing as the active components promotes wetting on the ceramic surface.

For active metal brazing the metallurgical bonding is the result of a chemical reaction between the reactive element in the brazing alloy and the ceramic surfaces.